McNamara, left, and President John F. Kennedy walk toward a pier in Hyannis Port, Mass., in July 1961. Kennedy was so impressed on meeting McNamara that he offered him a choice of leading the Defense Department or the Treasury Department. McNamara chose Defense.

McNamara, left, and President John F. Kennedy walk toward a pier in Hyannis Port, Mass., in July 1961. Kennedy was so impressed on meeting McNamara that he offered him a choice of leading the Defense Department or the Treasury Department. McNamara chose Defense. (John Rous / Associated Press)